Line usage recorder circuit



F. B. SPENCER ugf28, 1945.

` LINE USAGE RECORDER CIRCUIT Filed Mann 21, y1944 NSR QRO, 4

ausm.

y INVBNTOR AITORNEY Patented Aug. 28, 1945 LINE USAGE RECORDER CIRCUITFred-Bernard Spencer, Los Angeles, Calif., as-

signor to American Telephone and Telegraph Company, a corporation of NewYork Application March 21, 1944, Serial No. 527,416

6 Claims.

This invention relates generally to telephone systems and, moreparticularly, to arrangements vin telephone systems for recordingthenumber of calls made from a subscribers station lor for `recordingthe length of time that a subscribers station is in use for callsoriginating at the suby scribers station.4

i 4Dial central oices are generally designed so that each subscribersline appears before two sets .of switches, one set carrying callsoriginated by the subscribers station, and a different set car- Aryingterminating calls to be completed to the subscribers station. Means areprovided for shifting lines from one group of originating switches toanother without changing subscribers telephone numbers. It isaccordingly desirable to have-sinformation regarding the amount of timef that the lvarious lines are busy on originating calls j to aid inbalancing the loads carried by. different groups of originatingswitches. 1, Message registers are used in telephone systems to recordthe number of calls originating in' a subscribers station for which acharge is to be made. Such a message register may be operated undercontrol of an associated polarized relay ,connected in series with thesubscribersv line. The polarized relay is operated by a reversal of4.current which occurs after acall is completed, if the call originatesat the subscribers station I and is one for which a charge is to bemade. Such vmessage registers do not indicate the length of time that asubscribers station is in use, nor the number of calls that thesubscriber-may attempt to make in any given time interval.

Accordingly, it is an object of this invention to provide a simple andrelatively inexpensive arrangement for indicating the total time during`which a subscribers station may be in use on originating calls. Suchinformation obtained during busy hours from a number of subscribersstations in a given telephone central oliice Will be o fvalue indetermining whether the subscribers stations observed are overloading agroup of available lines of the central ofce and, therefore, whethersomeof those subscribers stations should notbe transferred to less heavilyloaded line groups. Such information may also be ofv value indetermining whether any of the lines are underloaded so that such linesmay likewise be redistributed to eiect a balanced load. Another objectof this invention is to Provide a. simple arrangement for indicating thenumber of..calls that a subscribers station is attempting .to makeduringanygiven time interval. i

The objects of this invention may be accomplished by two relaysconnected in a novel circuit arrangement to the ring and sleeveconductors at the central office. The rst of these relays is connectedto the sleeve conductor of the line to be observed; The second relay isconnected to thering conductor of the line through one of the armaturesof the first relay and its back contact. The second relay becomesoperated immediately after the subscriber removes his receiver from itsswitch-hook and remains operated, under control of the iirst relay,aslong as the receiver is off its switch-hook. When the subscriberstelephone set is connected to the selectors of the central oiiice, thesleeve conductor will become grounded so as to operate the first relay,but the second relay will be held operated. The second relay, whenoperated, actuates a timing lor register mechanism or circuit to recordthe time during which the subscribers line is busy during the calloriginated by the subscribers station. When the subscriber returns hisreceiver to its switch-hook at the end of the call, ground will beremoved from the sleeve conductor, thereby releasing the rst relayvwhichin turn will cause the second relay to be released calls received by thesubscribers station from another station will fail to operateA thetiming or register mechanism, The timing or register mechanism Vwillthus distinguish between incoming and outgoing calls, y

This invention will be better understood from the more detaileddescription hereinafter following, when read in connection with theaccompanying drawing which illustrates the invention applied generallyto a step-by-step telephone i system, although the invention is equallyapplicable to any other type of telephone system.

Referring to Figure 1 of the drawing, there is shown a dial subscriberstelephone set A connected to a line circuit LC at the central oiiicezThe line circuit LC-includes, among other things, a line relay LR and acutoi relay CO. The upper winding of the line relay LR connects groundto the tip conductor T through .the upper cuter armature and backcontact of relay CO. The lower winding of line relay LR connects batteryto 'the ring conductor R through the upper inner armature and backcontact of relay CO. The line of relay CO, conductor R, subscribers setA, conductor T, the upper outer armature and back contact of relay CO,the upper winding of relay LR and ground. The operation ofrelay- LR^controls the start circuit of a line finder ALF of well known type, whichwill hunt for the calling partys line. When the line finderLF has foundthe calling line, it extends the conductorsT, Rand S into the rstselector SC. The selector SC connects ground tothe sleeve conductorS,there- `by -makingthe line test busy to incoming calls, andoperating thecutoiirelay CO. Operation of the 'relay CO disconnects the windings ofrelay 'BR' from the line, causing relay LR to release Tand-i remove thefline finder start condition.

Upon dialing digits corresponding to the called partys set B lthecalling partys line will then be` cennectedin a well known mannerthrough 'the selector SC- andv then through a connector "such as'CCi tothe-'called partys'set B if it is?" idle.' The line finder (orti-unl;nder) LF, the selector'SC and-the connector CC1 maybe of any well knowntypes. TheA E. D. Butz Patent 2,021,286, issued November 19, l935-,iorexamplefshowssuitable forms ffoi these switching structures. -v y y Whenmeasurement'oi originating trac is desired the equipment belowA thevdotted linel is provided and is connected-to theR and S terminals 'ofthe line circuit as in'dicated. It is observed-li that the winding oirelay OC isconnectedftothe "ring conductor R throughlthe inner armatureand backcontactl of rel'aySL. The' winding of relay-SL isshown connectedtoV the sleeve con- 'ducto'r S. lThe two relays OC and SL are the174control relays at the central office for actuating the line usa-gerecorder equipmentfto determine the length of time that the subscribersset A is in; forc'alls'originating atthat telephoneI set,

as will'now'be described.

Whenthe'receiverl ofthe subscribers set A is 'removed iiron'iA its'switch-hook, ias"'already described, to complete ia call to a `distantsubscrib- 'er s` set B, for examplegtherelay OC willlbecome loperated'due tothe grounding'v oifvtfhve tip conductor T. v Thecircuit'compl'eted to operate relay 0c win include battery, thepw'indi'gofrelay oc,

'theinner armatureA andback contact ofxrelay SL,"'the" ring''conduct'orjRy the telephone set' A,

theti'p conductorjT, the.' upper outer armature 'and back Contact ofrelay CO, the .upper winding offrelay LR andground., In. operating,remy-ooparuauy. @loses a. inciting circuit for itself through its lowerinner armature and make contact. This locking circuitifor relay OC canbe'.

,cor-npleted only after relay SL'becomes operated. Ground will beapplied: to th'eisleeve conductor S when the line finder' finds thecalling partys rlinea-nd this ground'wili. bevinaintained aftervselector: SC and connector C01. arelseized: and the telephrme circuit iscompleted' to 'the called. party 's 'set`-B.V Thisv groundiris showngenerally at the connector CCL The rgrounding oi the sleeve conductorSf-will'l cause relay SLltooperateA over the register mechanism MR.

a circuit including battery, the winding of relay SL, and the groundedsleeve conductor S. The operation of relay SL will complete'the lockingpath for relay OC through the lower outer armature and make contact ofrelay SL. Relay OC will be held operated as long as relay SL is operatedand relay SL will in turn be held operated as long 'as sleeve conductorS is grounded.

' The operation of relay OC is accompanied by the periodic operation ofthe register circuit MR. The register circuit includes battery, thewinding of the magnet of register MR the lower outer armature and makecontact of relay OC, the armature of relay PR and its make contact aridground. The relay PR is periodically operated over a circuit includingbattery, the interrupter IT, the winding of relay PR and ground. Therelay PR. and interruptor IT constitute a pulsing circuit, operatingrelay PR at regular intervals of, for example, six seconds. When relayOC is operated, the magnet of the register MR will be operated at likeintervals of time. The

wheel controlled bythe armature of the magnet of register MR'will recordthe number of time intervals that relay. OC is operated. As relay OCoperates immediately after the receiver of telephone set A is removedfrom its switch-hook" to initiate a call, the register mechanism MR willsubmit readings from which the length of time that telephone setA is insuch use may be determined. When the-call is completed, relay OC willrelease and thereby stop the operation of On `incoming calls to thesubscribers set A from a telephone subscribers set such as C, asimilar'circuit will be completed by the central oice" equipmentincluding a connector' CO2- to vestablish the' necessaryv telephone pathbetween lground to sleeve conductor S occurs before the ,calledparty isrung and before he removes his receiverfrom its switchmook. This groundon the sleeve conductor S will operate relay SL over lay SL, vsleeveconductors, and' ground at GD. Thel operation of vrelay SL will open thecircuit to relay OC at the `back contactfof' the' lower inner; armatureof relay SL and thereby prevent the operation of' relay OC for theincoming' call.

It is observed that the winding of relay SL is connected to the sleeveterminal- S" and that the winding rof relay OC is connected to the` ringtermina-l through the inner armature and back contact' yof relay SL.outgoing call from sta;-

tiony A will operate relay OC before relay' SL be'- comesoperated. Onthe other hand, an incoming calli to station A will operate rela-y SLybefore r'elayl,OC' becomes operated. This arrangement'dis- `tirrguishesbetween incoming and outgoing calls `vvithoiul polarized?- relaystructures.

Outgoing callsY alone will; operate the register' apparatus ThevarrangersentV is simple andi inexpensive. Any number oi. thesearrangements can be connecte-d to aline finder group in" the"v central'officet'o'observe the line` usage times of the associated' telephonestations and to' determine' which of the various stations or'grcups'- ofstations' are overloaded (or underloaded) during the day or part of theday.

The relay SL should be adjusted so that the make contact of its lowerouter armature will be closed before the back contact of its lower innerarmature is opened. This will insure lthe'completion of the lockingcircuit for relay OC before the main operating circuit for relay SL isopened.

If the register mechanism MR is to furnish a record of the numberoftimes that the subscriber at station A attempts outgoing calls, thenthe relay PR and interrupter may be omitted. In that case the makecontact of the lower outer armature of relay OC will be connected toground (not shown). Each attempted outgoing call from station A willoperate relay OC once and each operation of relay OC will operate theregister mechanism MR once.

Although the arrangement of this invention has been shown and describedgenerally inconnection with step-by-step central oilice equipment, itwill be understood that the invention may be set up in other and widelyvaried organizations and may be applied to other types of telephone orsignaling systems, without departing from the spirit of the inventionand the scope of the appended claims.

What is claimed is:

1. In a telephone system, the combination of tip, ring and sleeveterminals, a subscribers set connected to said tip and ring terminals, arst relay having its winding connected to said sleeve terminal, a secondrelay having its winding connected to the ring terminal through thearmature and back contact of said rst relay, register mechanismcontrolled by said second relay, means responsive to a call initiated bysaid subscribers set to operate said second relay and to lock saidsecond relay, and means responsive to a call received by saidsubscribers set to operate said lirst relay Ato prevent the operation ofsaid second relay.

2. In a telephone system, the combination of a subscribers set, a firstrelay, a second relay, register mechanism controlled by said secondrelay, means responsive to the removal of the receiver of saidsubscribers set from itshook to initiate a call Ato operate said secondrelay and lock said second relay in its operated position, and meansresponsive to a call to said subscribers set to operate said first relayand to prevent the operation of said second relay.

3. Telephone apparatus comprising tip, ring and sleeve terminals, a rstsubscribers set connected to the tip and ring terminals, a second saidtip and ring terminals, a first relay having two armatures, the windingof said first relay being connected to said sleeve Iterminal andoperable when said sleeve terminal becomes grounded, a second relayconnected to thering terminal through one of the armatures of said rstrelay and its back contact, a locking circuit for said second relayextending through lthe other of the armatures of said rst relay and itsmake contact to the sleeve terminal, recording apparatus controlled bysaid second relay, means responsive to a call initiated from said Iirstsubscribers set lto operate said second relay, and means responsive to acall initiated by said second subscribers set to operate said rst relayand to prevent the operation of said second relay.

4. Telephone apparatus comprising tip, ring and sleeve terminals, asubscribers set connected `to said tip and ring terminals, a rst relaycontrolled by groundr applied to said sleeve terminal, a second relayconnected to the ring terminal through the armature of the first relayand its back contact, recordingr apparatus controlled by said secondrelay, means responsive 'to a call initiated by said subscribers set tooperate said second relay and said recording apparatus, and meansresponsive to a call received by said subscribers set to operate thefirst relay and to prevent the operation of said second relay.

5. Telephone line usage recorder apparatus fo'r a telephone subscrbersset, comprising tip, ring and sleeve terminals, a iirst relay connectedto said sleeve terminal and operated when the sleeve terminal becomesgrounded, a second relay connected to the ring terminal through thearmature and back Contact of said iirst relay, said second relay beingoperated when the subscribers receiver is removed from its switch-hook,land pulsing and recording apparatus controlled by said secondrelay.

6. In a step-by-step telephone system, the coml bination of tip, ringand sleeve terminals, a subset connected to the tip and ring conductors,a first relay connected to the sleeve terminal and operated only whenthe sleeve terminal becomes grounded, a second relay connected to thering terminal through the armature and back contact of said rst relayand operated when the receiver of the subset is remoyed from itsswitch-hook `to initiate a call, means responsive to the completion of acall from said subset to operate the rst relay and to lock the secondrelay in operated condition, and recording apparatus controlled by saidsecond relay.

FRED BERNARD SPENCER.

